Method of making an abrasive belt

ABSTRACT

There is disclosed a coated abrasive belt (17, FIG. 4) whose abrasive-particle grit-size, and/or backing material and/or adhesive can be determined by a supervisor or the user while the belt is in use from a color pattern (33, 35) on the belt. The pattern may consist of bands (33, 35) of one or more colors along the non-abrasive back of the belt. It may also include a colored abrasive surface (75, FIG. 5) produced by depositing, during the making of the belt, on the abrasive surface a colored adhesive and/or abrasive particles mixed with a coloring material.

United States Patent [151 3,656,265 Schaffner, Jr. [451 Apr. 18,1972

54] METHOD OF MAKING AN ABRASIVE OTHER PUBLICATIONS BELT [72] Inventor: Gus J. Schaffner, Jr., Pittsburgh, Pa. [73] Assignee: Schaffner Manufacturing (Iompany, Inc.,

Pittsburgh, Pa.

[22] Filed: Oct. 14, 1969 [21] Appl. No.: 866,283

[52] U.S. Cl ..51/295, 51/399, 51/206 [51] Int. Cl ..B24b1/00 [58] Field of Search ..5 H298, 295, 394, 400, 401

[56] References Cited UNITED STATES PATENTS 3,256,645 6/1966 Holdash ..51/206 2,479,929 8/1949 Harris ..5l/401 2,284,716 6/1942 Benner ..5l/400 X Principles of Tool Room Grinding, The Carborundum Company, 1945 p. 26

Primary Examiner-Harold D. Whitehead Attorney-Hymen Diamond [57] ABSTRACT There is disclosed a coated abrasive belt (17, FIG. 4) whose abrasive-particle grit-size, and/or backing material and/or adhesive can be determined by a supervisor or the user while the belt is in use from a color pattern (33, 35 on the belt. The pattern may consist of bands (33, 35) of one or more colors along the non-abrasive back of the belt. It may also include a colored abrasive surface (75, FIG. 5) produced by depositing, during the making of the belt, on the abrasive surface a colored adhesive and/or abrasive particles mixed with a coloring material.

1 Claims, 8 Drawing Figures METHOD OF MAKING AN ABRASIVE BELT BACKGROUND OF THE INVENTION This invention relates to work finishing as typified by grinding and polishing of work and has particular relationship to the art of coated abrasive belts. This invention is also applicable to coated abrasive discs, sheets, and rolls for grinding and polishing. In the interest of brevity, the words belt or belts are used in this application with the understanding that, to the extent applicable, they include within their scope discs, sheets, and rolls. The principal components of such a belt are a backing material or stock, an adhesive on at least one surface of the backing material, and an abrasive which consists of abrasive particles deposited on the adhesive and secured to the backing material by curing the adhesive. The backing material is typically vulcanized cellulose fiber of different thicknesses (typically 18 mils to 42 mils). The backing material may also be cloth or even paper and may be composites of cloth and paper and fiber. The adhesive typically may be cattle-hide glue, or a resin such as Urea-Formaldehydes, Phenol- Formaldehydes, Epoxies, Epoxy Esters, and the like. The abrasive is typically aluminum oxide or silicon carbide, but it may also be flint, emery, or garnet. Depending on the purpose which the belt is to serve, the particle or grit-size of the abrasive particles may vary over a wide range from mesh-number 600 to mesh number 12. During usage of a belt, the abrasive particles are broken up into smaller particles so that the grit size changes from a lower mesh number to a higher mesh number.

In the use of coated abrasive belts, it is desirable that the userof the belt, and particularly his supervisor, shall know the components of the belt in use. This information is particularly necessary. for the grit size. The use of a belt with a large grit size removes the material from the work at a high rate and where too large a grit size is used, by mistake or because a worker on piece work desires to enhance his pay, costly scrap may result. The components of coated abrasive belts, made in accordance with the teachings of the prior art, cannot readily be determined while the belts are in use moving at a high speed in engagement with the work. To determine the components of such belts, it is necessary to stop the finishing operation and examine the belt. This is not practicable from an economic standpoint.

It is an object of this invention to overcome the above described disadvantage of the prior art and to provide a coated abrasive belt whose components, and particularly whose grit-size, shall be readily determinable by inspection while the belt is in use in a finishing operation. It is also an object of this invention to provide a method for making such a coated abrasive belt.

SUMMARY OF THE INVENTION In accordance with this invention, a colored pattern is im' pressed on one or both surfaces of the coated abrasive belt. The coloring material forthis pattern may be of the fluorescent or luminescent type. The coloring material is of the type which does not deleteriously affect the work. This pattern is correlated with the components of the belt so that these components are readily determinable while the belt is in use. Typically, where it is desirable to identify only the grit size, only the abrasive surface of the belt may be colored to correspond to the grit size. This coloring may be effected by mixing a coloring material with the abrasive particles deposited on the web or with the adhesive deposited on the web. A pattern of colored bands may be impressed on the uncoated or smooth surface of the belt by appropriately ridged rollers dipped in the coloring material. This pattern of bands may, by the selection of colors, identify a number of components of the belt. Colored bands may also be sprayed on the abrasive or smooth surface of the belt.

In the use of a coated abrasive belt, particularly of the larger grit sizes, the particles are broken down and after use over a substantial time interval, the grit size of the belt is reduced to a substantially smaller magnitude. The use of a belt of smaller grit size, where a belt of larger grit size is required, is not likely to produce scrap. A belt may then bear a single pattern identifying the larger grit size without serious consequences. However, in the practice of this invention, provision may be made for determining by visual inspection that a belt of larger grit size, which has been used for some time, has become converted into a belt of smaller grit size. For this purpose, the color pattern includes two colors; one, corresponding to the smaller grit size, derived from coloring material mixed with the adhesive; and the other corresponding to the initial larger grit size, derived from coloring material mixed with the abrasive particles.

Initially, the color of the coloring matter mixed with the particles predominates and is identifiable. While the particles of larger grit size are being broken down, this coloring matter mixed with these particles is also removed. When the particles are reduced to smaller grit size, the color in the adhesive predominates and becomes identifiable.

BRIEF DESCRIPTION OF THE DRAWING For a more thorough understanding of this invention, both as to its organization and as to its method of operation, together with additional objects and advantages thereof, reference is made to the following description, taken in connection with the accompanying drawing, in which:

FIG. 1 is a diagrammatic view showing apparatus for producing a belt in accordance with this invention;

FIG. 2 is a fragmental view enlarged showing a part of apparatus with which a color pattern of bands is applied to the smooth surface of a belt in the practice of this invention;

FIG. 2A is a plan view with respect to FIG. 2, with the web broken away to show the pattern impressing rollers;

FIG. 3 is a plan view showing the smooth surface of a belt in accordance with this invention, produced with the apparatus shown in FIGS. 1, 2, and 2A;

FIG. 4 is a view in perspective, showing a belt in accordance with this invention in use in a finishing operation;

FIG. 5 is a view in perspective, showing another belt in accordance with this invention;

FIG. 6 is a view in transverse section of still another belt in accordance with this invention; and

FIG. 7 is a view partly in transverse section and partly diagrammatic, showing apparatus for producing a further belt in accordance wit this invention.

DESCRIPTION OF PROCESS AND EMBODIMENTS FIG. 1 shows apparatus for producing from a web 11 of backing stock or material derived from a roll or unwinder 13, a coated abrasive belt strip. A plurality of belts can be produced from such a strip. For this purpose, the coated abrasive belt strip is slit along its length to form a number of long strips each of the desired width. Sections of this strip are cut out and joined at the ends to form endless coated abrasive belts. The belts 15, l7, l9, and 21, shown respectively in FIGS. 3, 4, 5, and 6, are thus produced. The coated abrasive strip may also be cut into discs or sheets or the parts of rolls with templates.

The apparatus shown in FIG. 1 includes a printer 23 through which the web 11 passes from the unwinder 13. The printer 23 includes an ink vat 25 and a printing roll 27, which prints at intervals on the face of the web 11, that is to be smooth, the manufacturers identification 29, which may take the form shown in FIG. 3 and printed at intervals across the width of the belt.

The web 11 is then reversed by rollers 51 and 53 and passed through a making machine 55 where a wet adhesive coating is applied to the face of the web 11 opposite to the face bearing the marks 29. The making machine 55 includes a hopper 57 for mixing the adhesive. The hopper 57 deposits the adhesive in a vat 59 in which a roller 61, in engagement with the web 11, is rotatable. The roller 61 deposits a wet film of adhesive on the unmarked surface of the web 11. The adhesive may contain appropriate coloring material to produce a color pattern 63 as shown in FIG. 6. This pattern may identify the initial grit size deposited, or it may identify the smaller grit-size which is produced after continued use of a belt.

The web 11 is then passed through an electrostatic coater 65. This coater includes a continuous belt 67 on which the abrasiveparticles are uniformly deposited through a hopper 69. The particles may be deposited through a vibrating screen (not shown) for uniformity. The web 1 1 is guided by rollers 71 so that it is generally parallel to the surface of the belt 67 on which the particles are deposited by hopper 69. An electrostatic field is applied to the particles by plates 73. This field charges the particles and attracts them to the face of the web 11 hearing the adhesive film. The particles being of the same polarity tend to mutually repel each other so that the deposit is uniform.

The particles may be mixed with coloring material, typically identifying the grit size. Colored abrasive surfaces 75 (FIG. 5) and 77 (FIG. 6) are thus produced. The color of abrasive layer 77 may be the same as the color of adhesive layer 63, or layer 77 may have a color corresponding to a greater grit size than the color of layer 63.

The web 11 is then passed through a precun'ng heater 81 where the web 11 is suspended while moving in festoons (not shown) while subjected to controlled heating. Next the web 11 is passed through a sizing machine 83 where a sizing adhesive coating is applied to the abrasive surface by a roller 85, which rotates in a vat 87 of sizing adhesive. The sizing adhesive may contain coloring material typically the same as the abrasive particles, or in lieu of the abrasive particles. The web 11 is next passed festooned (not shown) through a curing or setting heater 89, where the adhesive is dried (for some adhesives) or may be subject to an elaborate curing and conditioning operation (for others). The set, dried, or cured web is wound on a rewinder 91. To produce belts, sections of the strip 11 are used. The width of a belt is only a fraction of the width of the coated abrasive strip on rewinder 91. The strip 91 is first slit lengthwise into a number of long coated abrasive strips 101. Each strip 101 may be provided with color bands 33 and 35, along the center and along the edges of its smooth (or abrasive) surface with apparatus as shown in FIGS. 2 and 2A. For this purpose, the strip 101 is passed through the pattern impresser 31, from an unwinder (not shown) to a rewinder (not shown). A color pattern in the form of color bands 33 and 35 (FIGS. 4 and 5) are impressed along the center and along the edges of the smooth face of the strip 101. The pattern impresser 31 includes vats 37 and 39 of appropriate coloring materials. In addition, there are ridged rollers 41 and 43 (FIG. 2A), which are rotated through the materials in the vats 37 and 39 and in contact with the smooth surface of the strip 101. Roller 41 has ridges 45 at its ends and produces the edge bands 35, and roller 43 has a center ridge 47 and produces the center band 33. The impresser 31 may also operate with one or more smooth (unridged) rollers which impress a uniform color on the smooth surface of the strip 101.

After the strip 101 is color coded as shown in FIGS. 2, 2A and 3, the strip 101 is cut into sections of appropriate length and the ends of the sections are joined to form belts.

Where discs, sheets, or rolls are to be formed, the desired forms may be cut from the wide strip 11 with templates.

Band patterns similar to the pattern 33-35 may be impressed on the abrasive face of the strip 101 as shown in FIG. 7. For this purpose, coloring materials may be sprayed on the abrasive face of the strip after it is cured by spray guns 92. The guns 93 may be interposed between the curing heater 89 and the rewinder 91. The guns 97 may also be positioned to produce a single color.

In use, a belt 17 (FIG. 4) moves at a high speed in engagement with work 93. The components of the belt may be determined from the pattern 33, 35 and/or from the color of the abrasive surface 95.

While preferred embodiments of this invention have been disclosed herein, many modifications thereof are feasible. This invention is not to be restricted, except insofar as is necessitated by the spirit of the prior art.

lclaim:

1. The method of making an abrasive belt with backing material in the form of a web which comprises, providing a wet adhesive, placing in said adhesive a coloring material of one color, said color being selected to correspond to a fine grit, passing said web through said wet colored adhesive material and coating at least one surface of said web, thereafter providing abrasive particles with a second and different coloring material, said second coloring material being selected to identify a coarse grit of said abrasive particles, depositing said abrasive particles combined with second coloring material an said colored adhesive material so as to completely cover said colored adhesive material, then curing said adhesive material, and thereafter forming a belt of the web with the cured adhesive material, abrasive particles thereon and with the belt reflecting said second color from its abrasive surface. 

